Steps taken by Yahoo to safeguard its Yahoo Messenger instant messaging (IM) service from spammers are also disrupting the legitimate use of the popular Trillian application.
Trillian is an application made by Cerulean Studios that lets end users manage multiple IM accounts from a single IM console on their PCs.
Software such as the Trillian application can allow a user to have Yahoo, AOL and Microsoft IM buddies all listed. Trillian has about 940,000 users in the US in July and is the most popular software of its kind.
Yahoo upgraded its Yahoo Messenger service in June by adding features designed to prevent IM spamming and gave its users until 24 September to upgrade to this version.
However, the latest version of Yahoo Messenger does not work well with the Trillian application. Cerulean Studios has acknowledged the problem and is working to resolve it.
A Yahoo spokeswoman said the upgrade could disrupt third-party software and services that aim to interoperate with Yahoo Messenger.
"Our primary goal for the update is to prevent spammers from spamming our users. If this upgrade affects the way in which other services interact with Yahoo Messenger, it is a by-product of our efforts to protect users from spammers," said Mary Osako, Yahoo's director of communications.
Yahoo believed its users would appreciate the spam protection, even if these efforts cause other inconveniences. Yahoo is receptive to talking to other companies "that share our goal of opening IM communications in a seamless, secure and convenient manner", she added.
Juan Carlos Perez writes for IDG News Service